The crash occurred just after 4 a.m. at the Crown Point exit as traffic backed up because a car was being towed from the interstate, state police said.A flat-bed semi and a Dodge pick-up truck carrying the family was stopped when a semi with double-box trailers came over a hill and could not stop in time, hitting the pick-up and pushing it into the back of the flat-bed, state police said.

The pick-up caught fire and the blaze spread to semi that hit it, police said.

The family was pronounced dead at the scene by the Lake County Coroner's office. The driver of the semi was able to escape unharmed.

Crews work to clear a charred Dodge pick-up truck that was struck by a semi and burst into flames on I-65 at Crown Point, killing all five family members inside. (Indiana State Police)